Process of and apparatus for making metal sheets



March 5, 1929. H. c. HARRISON PROCESS OF AND APPARATUS FOR MAKING METAL SHEETS Original Filed Dec.l 4, 1923 3 Sheets-Sheet l Lison March 5, 192.9.. H, C, HARR|5ON 1,704,247

PROCESS 0F AND APPARATUS FOR MAKING METAL SHEETS Original Filed Deo'. 4, 1923 3 Sheets-Sheet 2 Z/LLIULJ 2/ g I m g 11. Harrison March 5, 1929. H, C, HARRlsON 1,704,247

PROCESS 0F AND APPARATUS FOR MAKING METAL SHEETS original Filed Dec. 4, 192:5 s sheets-Sheet 5 lf A Jaa/mx Patented Mar. 5, 1929.

UNITED STATES PATENT OFFICE.

HERBERT CHAMPION HARRISON, OF LOCXPORT, NEW YORK; FLORENCE I. HARRISON, ARTHUR BRIDGES BBANFIL HARRISON, AND WILLIAM 'WHITHORE CAHPBELL TRUSTEES OF SAID HERBERT CHAMPION HARRISON, DECEASED.

PROCESS OF AND APPARATUS FOR m@ HETAL SHEETS.

Application led December 4, 1923, Serial No. 678,458. Renewed September 8, 1925.

This invention relates to a process 'of and an apparatus for making wide electrolytic copper sheets in long lengths,`and has for its object to provide a procedure and a means which will be more eiiicient in use, and less costly to construct than those heretofore proposed.

With these and other objects in view, the invention consists in the novel steps and coinbinations ot steps constituting the process, and in the novel parts and combinations of parts constituting the apparatus, all as will be more fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanying drawings forming a part et this specilication, in which like numerals designate like parts in all the views:

Figure l is a diagrammatic View, taken on the line 1`1 ot Figure 2, looking in the direction ot the arrows, and showing an apparatus made in accordance with this invention ure 2 is a sectional plan view taken on the line 22 ot Figure l;

Figure 3 is a sectional view,vtaken on .the line 3--3 oit Figure 1, looking in the direction oi' the arrows; and t Figure t is an end elevational view of the parts shown in Figure 2.

In order that the precise invention may be the more clearly understood, it is said: Very thin copper sheets, of about, say, five onethousandths (.005) to ten one-thousandths (.010) of an inch in thickness, and of comparatively large dimensions, of say from to 150 feet long or longer, and several feet wide, would he in great demand commen cially Jfor a variety of purposes, among them that ot furnishing the strips for manufac-v turing radiators toi' use on motor vehicles, it such sheets could he supplied at a cost sutlicieiitly low `to compete with brass sheets or strips. But at present brass strips are almost universally used, and in enormous quantities. owing to their lower cost, notwithstanding the recognized advantages possessed by the copper sheets or strips for this and other purposes. Prior to this invention, itV has been proposed to employ a number ot' different kinds of cells for the electrodeposition of copper sheets or strips, involving stationary as well as revolving eathodes, and circulating electrolytes, etc., but in so far as I am aware, no one prior to this invention has been able to produce very thin commercial'copper sheets approaching the dimensions abovestated, nor in fact any thin metal sheets or strips which could be commercially substituted for the well known brass strips now employed in the manufacture of automobile radiator cores.

According to this invention, on the other h and, one is enabled to overcome the difficulties heretofore encountered, and to not only produce co per sheets and strips at costs as low as t e brass sheets and strips above mentioned, but at somewhat lesser costs, all as will presently appear.

Referring to the accompanyin drawings: Figure l represents any suitab e container lined with lead or other suitable material 2 and in said container is suitably mounted the anode baskets or containers 3 which are also preferably made of sheet lead material. Said containers 3 are preferably of the L shapes shown, and provided with shorter upturned flanges 4, and with longer upturned flanges 5, as shown. Associated with the lead lining 2 are the inverted L-shaped members 6 pro-A vided with horizontally disposed portions 7 and downwardly extending flanges 8 which are conveniently secured to the flanges 9 of the lead lining 2, as indicated at 10. These said members 6 are so disposed that their said top portions 7 are located well above the level of tlie electrolyte, for a purpose that will presently appear. Said portions 7 of the members 6 are provided with suitable openings 12 for the escape of air as will presently appear. The upturned flanges 5 of theanode containers extend upwardly into the chamber formed by the members 6, as shown, so

as to form two channels or passages indicated respectively by the numerals 13 and 14, In the cell or receptacle 1 is suitably supported, as will presently appear, thev catihode 16, which in this instance is preferably iliade cylindrical in forin; but of course other forms may be adopted if desired. This cathode cylinder 16 is conveniently made hollow and of plaster of Paris or other suitable material, and is provided at each end with the metallic conducting rings 17, having flanges 18, which extend into the hollow space 20 of the cathode 16, beyond the inner wall surface 19 thereof, as will be clear from Fi res 1 and 3. 21 represents a bus bar, which extends across the top of the cell or receptacle 1, and through said hollow Space 20 of the cathode,

so that the contacting flanges 18 of the ringsl 17 rest upon said bus bar 21, and thus support the cathode in the cell or receptacle l, all as will be clear from the drawings. Partially surrounding the cathode 16 are a pair of porous partition members 22, whose lower sides or edges 23 rest in supports 24, with which the upturned flanges 4 ofthe anode receptacles or baskets 3 are provided. The end edges 25` of said porous part1t1or 1s 22 are conveniently supported in the lead lining 2 of the cell 1, as by the ribs 26 illustrated.

These porous partitions 22 are so dlspo'sed and fixed in position that they form restricted passages 27 between the anode chambers 28 and the rotating cathode surface 29 as shown. Further, the shorter upturned ianges 4 of the anode baskets 3 are so spaced apart as to form a passage 30 leading from the restricted passages 27 into the wider horizon` tally disposed passa-ges 31, as best illustrated in Figure 1.

Leading down through the tops 7 of the members 6 are a pair of air conveying pipes 33, provided with perforated right angular extensions 34, adapted to deliver air near the bottoms of the passages 13 beneath the surface or level 36 of the electrolyte, and this air bubbles up through the electrolyte and enters the air-settling tanks 37 formed by the tops of said inverted Lshaped members 6 located above the surface 36 of said electrolyte as shown. The air, after entering said settling tanks 37 may escape through the perforations 12, as will be readily understood; but the motion thus imparted to the electrolyte causes the latter to flow over` the tops 50 of the flanges or partitions 5, and .downwardly through the passages 14 into the anode receptacles 28, whereupon the moving electrolyte will strike the convex sides of the porous partition 22, and flow upwardly and over the top edges of said partitions into the restricted passage 27 and into the passages 30 and 31, and then flow back to and past the perforated extensions 34 of said pipes 33, to be again circulated over the same paths.

The air being under pressure, maintains a continuous circulation of thel electrolyte through the restricted passages 27 and over the surface of the cathode 16, and thus causes the concentration of the electrolyte on that surface to be maintained constant. The anode chambers 28 or basket-s 3 are kept filled with soluble anode material 52, such as copper, copper scrap, copper shot, etc., and the porous partitions 22 serve to maintain constant the distance of the said soluble material from the cathode surface. In other words, it is evident that, no matter how fast or slow or unevenly, the copper anode material 52 may be dissolved, some of it will always contact with the convex surfaces of the porous partitions 22, and thus will be at a substantially uniform ldistance and Vresistance from the said cathode surface. This feature coupled with the continuously circulating electrolyte of al uniform concentration through the restricted passages 27, serves to greatly improve the character of the deposit on said cathode.

The cathode surface 29 may be made conveniently of copper, which may be electroplated upon the plaster of Paris, or otherwise attached thereto. This surface should be in electrical connection with the rings 17 and highly polished. l/Vhen it is desired, said surface 29 may be coated with a suitable liquid toA prevent the electro-plated sheets from sticking thereto. Onesuch liquid is found in a very dilute solution of paraiiine wax in carbon tetrachloride.

@wing to the fact that a considerable portion of the surface of the cathode 16 is disposed above the level 36 of the electrolyte, and further owing to the fact that the deposited sheet 40 is stripped from the cathode surface at a point 41 above the level 36 of the electrolyte, the surface 29 of said cathode above said electrolyte is maintained clean and dry, so that it can be readil coated continuously with the above mentioned solution, in any suitable manner, as by the application of a brush as indicated at 53.

It is referred to maintain the electrolyte at a pre etermined constant temperature, and a convenient way of doing this consists in heating the air before it is delivered through the pipes 33 to the required temperature. In fact, the air delivered in the manner disclosed performs not only the function of circulating the electrolyte as described, and that of maintaining the latter at a predetermined temperature, but-it further saturates the electrolyte with air, which greatly improves the character of the deposit. rl`hat is to say, as is well known, any free air in the electrolyte is very detrimental to the character of the deposit, while dissolved or saturating air is beneficial. In the apparatus disclosed, after the air has been delivered beneath the surface of the electrolyte, it saturates the latter, and the surplus of free air leaves said electrolyte to enter the settling tanks 37. This action frees the electrolyte of any undissolved air by separating it out upwards under the action of gravity of the liquid.

After a sufficiently thick deposit of copper is had upon the cathode surface 29, it is partially stripped from said surface, and the sheet 40 thus produced is passed between rolls 42 and 43, through the curved guides 44, and allowed to coil itself about the mandrel 45, as

illustrated. One of the rolls, such as 42, is

conveniently rotated by a power means, not shown, and the speed at which said roll is driven is so governed as to cause that portion of the deposited sheet which has not been drawn off to remain in the bath a sufficient llU length of time to become of the thickness rcquired. In other words, the cathode 16 is almost stationary, and is very slowly revolved due to the pull of the roll 42 on the sheet 40.

The o eration of the electrolytie cell 1 will be clear rom the foregoing, but may be briefly summarized as follows:

The current may be conveniently led into the cell from the anode bus bar 60 wliei'eupon it traverses the lead lining 2 the anode baskets 3 and the soluble anode material 52. As said v current passes through the electrolyte, it

reaches the cathode surface 29 depositing the sheet 40, and leaves the system through the bus bar 21, all as will be clear from the drawings.

It is an important feature of this invention that the anode material 52 is kept by the porous partitions 22 at asubstantially uniform distance from the cathode surface 29 and thus maintains the resistance constant between the anode and cathode surfaces. It is another important feature of the invention that the electrolyte is constantly circulated through the restricted passages 27 over said cathode surface, and thus maintains the concentration of said electrolyte on said surface constant. It is further an important feature of this invention that the electrolyte thus cir culated through the restricted passages 27 is saturated with air, and is also maintained at a predetermined constant temperature as described. It is a still further important feature of the invention that the speed of rotation of the roll 42, and therefore the speed of rotation of the surface 29 is so governed as to cause the required thickness of the sheet 40 to be deposited during the period elapsing between the entrance of a given port-ion of said cathode surface into the electrolyte and its emergence therefrom. Another important feature of the invention resides in the partial submergence of the Cathode surface 29 in the electrolyte, and the stripping of the sheet 40 from said surface outside said electrolyte, for the freshly stripped portion 63 of said surface is dry and clean, and can be easily kept coated as by means of the brush 58 with a liquid which will prevent the deposited sheet from sticking to said surface 29.

Owing to the above important features of this invention, one is enabled to continuously produce commercially thin, coherent, strong and. elastic continuous sheets of copper between five one-thousandths of an inch and ten one-thousandtlis of an inch thick, and at a cost which is even less than the corres ending brass material. Other thin metal s ieets of course, can be produced at various other costs.

It will now be clear that this invention differs from those which have gone before in the following particulars: That is to say, prior workers in this field have recognized that in the operation of electrolytie cells for the making of metallic sheet material it is Very desirable indeed, to employ high current densities and for a number of reasons, among them in order to reduce the capital outlay in the plant, and to reduce the necessary supervision of the process. They have also employed the well known expedients of rotating the cathode or the anode at high velocities in order to renew the electrolyte at the surfaces of the electrodes. cedures, it has been further recognized that for the making of wide, long, and thin' metal sheets, of the nature here disclosed` no commercial process had been evolved due to the well known objections inherent in said prior procedures, among them the apparent necessity of employing a stationary cathode, and a continuous stripping operation from .said cathode, which two conditions seemed impossible of attainment. In addition to this, it seemed in the prior procedures not possible to flow the electrolyte past the stationary cathode surface with a speed sufficiently high to satisfactorily renew said electrolyte when using the required high current densities, nor did it seem possible to maintain the distance constant between the rapidly dissolving anode surface and the cathode surface. By following the procedure outlinedabove, however, all these objections are overcome, because the cathode surface 29 is substantially stationary for its revolution under ordinary conditions Will take say an hour, or more; the stripping operation is continuous for the sheet 40 is slowly but continuously pulled on and moved by the roller 42; the electrolyte is readily given any speed desired in its passage over the cathode surface 29, for the passages 27 are made sufficiently restricted and the pressure of the air in the pipes 33 is madesufliciently high to accomplish this; and the distance between the anode and cathode surfaces is kept substantially constant because the anode material is always contacting with the porous partitions 22. D

Inso faras I am aware, no one prior to this invention has combined the foregoing features in an electrodeposting cell of this nature, and by combining these said features I find that one is enabled to readily use high current densities, to make a uniform deposit,

to continuously run the cells, and to make coherent commercially strong and uniform thin metallic, sheets of copper which can com pete with the brass sheets heretofore cmploved.

Of course, in a large plant more than one But in all such prior pro-y cell is essential to produce the quantity of material required, and therefore the cell 1 is connected up with a sufficient number of other cells 70 to furnish the output of sheets required. A convenient method of connecting these cells is that illustrated. That is to say, the cathode bus bar of one cell 21 is extended and forms theanode bus bar 7 5 of a succeeding cell. In order to cut out one cell from another any suitable switch mechanism 76 may be employed.

It is obvious that those skilled in the art may vary the details of construction as well as the process disclosed, without departing from the spirit of the invention, and therefore it is not wished to be limited to the above description except as may be required by the claims.

What is claimed is:

1. The process of improving the character of the deposit in making thin metal sheets from soluble anode material, which consists in providing a continuously rotating cathode Surface; from which said sheet is stripped; separating said surface from said soluble material by a fixed porous partition conforming to the contour of said cathode surface, whereby said soluble material is always maintained in substantially the same relation to said cathode, and causing the stripped sheet to continuously rotate said surface.

2. In an apparatus for electro-depositing a continuous thin metal sheet, the combination of a container; an electrolyte in said container; a cathode surface extending above the level of said electrolyte and moving in a closedgpath; an anode chamber provided with soluble anode material; a non-conducting chemically inert porous partition separating said anode chamber from said cathode surface; and means for circulating an air-saturated electrolyte over said surface.

3. In an apparatus for electro-depositing a continuous thin metal sheet, the combination of a container; an electrolyte in said container; a cathode surface extending above the level of said electrolyte and moving in a closed path; an anode chamber provided with soluble anode material; a n0n-conducting chemically inert porous partition spaced from and separating said anode chamber from said cathode surface to provide a restricted passage between the cathode surface and said partition; and means for saturating with air and circulating said electrolyte containing said air through said passage.

4. In an apparatus for electro-depositing a continuous thin metal sheet, the combination of a container; an electrolyte in said container; a cathode surface extending above the level of said electrolyte and moved in a closed nath by the sheet stripped therefrom; au anode chamber provided with soluble anode material; and a non-conducting chemically inert porous partition separating said anode chamber from said cathode surface.

5. In an` apparatus for electro-depositing a continuous thin metal sheet, the combina* tion of a container; an electrolyte in said container; a cathode surface extending above the level of said electrolyte, said surface traversing a closed path and rotated by the sheet removed therefrom; an anode chamber provided with soluble anode material; and

means for circulating said electrolyte over said cathode surface.l

6. In an apparatus for electro-depositing a continuous thin metal sheet, the combination of a container; an electrolyte in said container; a cathode surface extending above the level of said electrolyte and moving in a closed path; an anode chamber provided with soluble anode material; a non-conducting chemically inert porous partition spaced from and separating said anode chamber from said cathode surface, to provide a passage between the cathode surface and said partition; and means for circulatingr said electrolyte through said passage.

7. In an apparatus for electro-depositing a continuous thin metal sheet, the combination of a container,-an electrolyte in said container; a cathode surface extending above the level of said electrolyte and moving in a closed path; an anode chamber provided with soluble anode material; a non-conducting chemically inert porous partition separating said anode chamber from said cathode sur'- face; and means comprising a source of air under pressure for circulating said electrolyte over said cathode surface.

8. Inan apparatus for electro-depositing a continuous thin metal sheet, the combination of a container; an electrolyte in said con* tainer; a cathode surface extending over the level of said electrolyte and moving in a closed path; an anode chamber provided with soluble anode material; a non-conducting chemically inert porous partition separating said anode chamber from said cathode surface; and means for continuously stripping said deposited sheet from said cathode surface after it has left the electrolyte and from a point above the level of the same.

9. In an apparatus for electro-depositing a continuous thin metal sheet, the combination of a container; an electrolyte in said container; a horizontally disposed cylindrical rotatable cathode in said container projecting above the level of said electrolyte; an anode chamber in said container provided with a porous wall separating' it from and conforn'iing to the surface of said cathode; and means for continuously stripping said deposited sheet from said cathode at a point above the level of said electrolyte.

l0. In a cell provided with an electrolyte, the combination of a container; a horizontally disposed cylindrical cathode in said container projecting above the level of the electrolyte therein; an anode; a porous partition between said anode and said cathode; means to continuously circulate said electrolyte over said cathode; and means to continuously rotate said cathode. Y

ll. In an apparatus for electro-depositing a continuous thin metal sheet, the combination of a container; an electrolyte in said container; a horizontally disposed cylindrical rotatable cathode in said container projecting above the level of said electrolyte; an anode chamber in said container provided with a orous wall se arating it from and conforming to the sur ace of said cathode; means for stripping said deposited sheet from said cathode at a oint above the level of said electrolyte; an means to continuously circulate said electrolyte from said anode chamber over said cathode surface.

12. In an a aratus for electro-de ositing a continuous t 1n metal sheet, the com ination oi' a container; an electrolyte in said container; a horizontally dis osed cylindrical rotatable cathode in sai container projecting above the level of said electrolyte; an anode chamber in said container provided with a porous Wall separating it from and conforming to the surface of said cathode; means for stripping said deposited sheet from said cathode at a point above the level of said electrolyte; and means adapted to continuously circulate said electrolyte from said anode chamber over said cathode surface, while controll ling the temperature of said electrolyte.

13. In an apparatus for electro-depositing a continuous thin metal sheet, the combination of a container; an electrolyte in said container; a horizontally disposed cylindrical cathode in said container projecting above the level of said electrolyte and rotated by the sheet stripped therefrom; and an anode chamber in said container provided with a porous Wall separating it from and conforming to the surface of said cathode, to provide a restricted passage between the cathode suri face and said partition.

14. In an electrolytic cell, the combination of a container an electrolyte in said container; an air-settling tank dis osed above said electrolyte; a plurality of ailles creating a plurality of tortuons passages associated with said tank; a cathode associated 'with said electrolyte; and means for bubbling air up through said electr-ol te into said tank, whereby the motion t us imparted to said electrolyte, causes the latter to flow through said passages and past said cathode.

15. In an electrol tic cell, the combination of a container; an e ectrolyte in said container; an air-settling tank disposed above said electrolyte; acathode partially immersed in said electrolyte; a porous partition spaced from said cathode, forming a restricted passage for the electrolyte; and means for bubbling air up through said electrolyte into said tank; whereby t 1e motion thus produced causes said electrolyte to circulate over said cathode through sa1d restricted passage.

16. In an apparatus for electro-depositing a continuous thin copper sheet, the combination ot' a cathode; an L-shaped member for holding soluble anode material; a porous partition separating said L-shaped member from said cathode; and means to circulate an electrolyte from said anode material over said cathode.

17. The process of producing a thin metal sheet which consists in continuously electrodepositing said sheet'on a partially immersed cathode surface; stripping said sheet from said surface after it has left the electrolyte v and from a point above the level of the same;

over said surface during the depositing operation.

In testimony whereof I aix my signature.

HERBERT CHAMPION HARRISON. 

